Some magnetic information medium recording/reproducing devices are used for reading and writing information from and on a flexible magnetic recording medium whose medium length is long. A type of flexible magnetic information media is a boarding pass for a passenger aircraft which is a paper magnetic card with a long card length. Data are read and written from and on the flexible magnetic information medium. Various data such as a departure place and a destination are recorded as magnetic information on a boarding pass. The data are read by a magnetic card reader provided at the entrance gate of an airport and new data are written if necessary. The size of a two-head type of magnetic information medium recording/reproducing device becomes larger because a feeding path corresponding to the length of a magnetic recording medium is required. On the other hand, in a type of magnetic information medium recording/reproducing device with one head for both reading and writing, a magnetic recording medium is reciprocated and thus a long processing time is required.
In order to solve the above-mentioned problems, a magnetic information medium recording/reproducing device has been proposed in which a series of information processing such as reading/writing/collation of information for a magnetic recording medium are successively processed while the magnetic information medium is sandwiched and carried between the outer peripheral face of a drum and a feeding mechanism disposed around the drum (see Japanese Patent No. 2,810,600 and Japanese Utility Model Registration No. 2,549,807).
A magnetic card reader as described above which processes a magnetic information medium is constructed, for example, as a magnetic information medium recording/reproducing device described below. In other words, this device includes a turnable drum, a feeding mechanism disposed so as to face the outer peripheral face of the drum, a magnetic head disposed to face the outer peripheral face of the drum and the like. In this device, a magnetic information medium is carried along the outer peripheral face of the drum while magnetic information is read with a magnetic head or magnetic information is newly written.
This device is constructed, as shown in FIG. 9, such that feeding mechanisms 103, 104 including flat belts are disposed around a drum 102 which is turnable around a rotation shaft 101 to form a ring-shaped feeding path where a magnetic recording medium is sandwiched between the drum 102 and the feeding mechanisms 103, 104 and circulatively traveled in one direction. Reading or writing of data is successively executed from or on a magnetic recording medium which circulates around the drum 102 by a read/write head 105 which is disposed on the mid way. The feeding direction of the magnetic recording medium is appropriately changed by the operation of flappers 106, 107 disposed in the middle of the feeding path depending on the presence of a defect of recorded information on the magnetic recording medium, the requirement of writing of information or the like, and a prescribed magnetic processing is performed or the magnetic recording medium is sent out from a card eject passage 108. Further, in the case that the magnetic recording medium is abnormal, the magnetic recording medium is returned to a card insertion port 109 and ejected by reverse movement of the feeding mechanism 103, 104.
However, in a magnetic information medium recording/reproducing device shown in FIG. 9, since a solid drum is supported with only a center shaft and turned, wobbling occurs. In addition, in the solid drum structure, since the weight of the drum itself is large, the wobbling is further increased. Therefore, it is difficult that positional relationship between the magnetic recording medium traveling on the outer peripheral face of the drum and the magnetic head is maintained in a constant state and thus the writing/reading output of magnetic data becomes unstable. In order to solve the problem, drum working and bearings with a high degree of accuracy are required to restrict wobbling of the drum and thus cost is increased.
Further, in the solid drum structure, the weight of drum itself becomes large and thus its inertia is also increased. Therefore, it is difficult for the drum to be alternately repeated with forward and reverse turnings during a short time. In other words, it is difficult that reading/writing/collating etc. of information are successively processed by forwarding and returning the magnetic information medium. Therefore, these processings are required to be performed while the drum is turned in one direction and thus a processing time becomes longer because unnecessary turning is needed. In addition, since the weight of the drum itself is large, a motor with a large torque, i.e., an expensive motor is required to be used.
Further, an insert port and an eject port for a magnetic information medium are required to be disposed on an extended side in a tangential and turning direction with respect to the ring-shaped feeding path through which a magnetic information medium is circulated in one direction. Therefore, the arrangement of the insert port and the eject port and the position of flappers cannot be freely designed and thus the size of the device is increased.
Moreover, since all components such as a drive motor are required to be disposed around a solid drum, spaces for arranging these components are needed and thus the size of the device is further increased.
Further, in the case that a magnetic information medium is sandwiched and carried between the outer peripheral face of the drum and the feeding mechanisms (for example, a flat belt) as described above, since the magnetic information medium is made of a paper, it is difficult to cut the magnetic information medium in a longitudinal direction and a short-sized direction with a high degree of dimensional accuracy. Further, the dimension of the magnetic information medium may expand or contract due to humidity, and thus it is not certain that the magnetic information medium moves on the magnetic head side and the magnetic tracks of the magnetic information medium always pass through specified positions. Therefore, the positional accuracy for track at the time of reading and writing operations of magnetic information is not sufficient.
Further, when it is difficult to keep the positional relationship between the drum and the magnetic head to be in a constant state, it is conceivable that the side face of the magnetic information medium is pushed by using a pressing member so as to pass through a specified position at all times. However, since the magnetic information medium is formed of paper, the paper is easily bent or its side edge is damaged with a strong pressure and thus the magnetic information medium is difficult to be carried at a constant position with respect to the magnetic head. Therefore, the output at the time of writing or reading of magnetic information is unstable.